A while back, Bilibili got flooded with videos with basically the same title — mostly “I built a tiny game console” or “I made my own retro handheld.” Most of these handhelds look surprisingly well designed and are genuinely tiny. Usually a 2.8-inch screen, two buttons (A and B), and a TF card slot for the system and data. The designers generally open-source their models and files, so you can print and build one yourself. They do look pretty nice.